Isolation, Characterization and Molecular Identification of Myxobacteria From Two Outermost Islands of Indonesia

Myxobacteria are Gram negative bacteria commonly found in soil, tree bark, and decay wood. These bacteria have unique social behaviors by forming fruiting bodies, moving by gliding motility and preying on other microorganisms. The research was conducted to isolate, characterize, and identify indigenous myxobacteria from Sumba and Papua Islands of Indonesia as a preliminary step to utilize their potential in the pharmaceutical industry. Myxobacteria were isolated using filter paper and baiting with Escherichia coli to obtain cellulolytic and bacteriolytic myxobacteria, respectively. Characterization of myxobacteria was performed with Gram staining, observation on pigmentation, morphology of vegetative cells, fruiting bodies, and myxospores. Molecular identification was conducted based on 16S rRNA gene sequence analysis. A total of 10 myxobacterial strains were successfully isolated and purified. All isolates obtained were Gram negative, rod shaped with yellow or orange pigmentation. Fruiting bodies observed contained spherical myxospores. Molecular identification of these bacterial strains showed that they belong to myxobacteria from suborder Cystobacterineae, namely Myxococcus fulvus, Myxococcus stipitatus, and Melittangium lichenicola. To our knowledge, this is the first record of their occurrence in Indonesia

Purifikasi Inhibitor Atpase/rna Helikase Virus Japanese Encephalitis dari Streptomyces Chartreusis

Japanese encephalitis virus (JEV) is a neuropathogenic virus commonly caused cen-tral nervous diseases such as meningitis and severe encephalitis. Although vaccine has been developed, no specific and effective drug is available so far. We previouslycarried out a screening of inhibitor of JEV RNA helicase, an enzyme that essential for virus replication, from Actinomycetes and found that Streptomyces chartreusis produce the inhibitor of JEV RNA helicase. In this study, an extracellular proteinwhich has inhibition activity on ATPase activity of JEV RNA helicase was purified from supernatant of Streptomyces chartreusis culture by ammonium sulfate pre-cipitation and size exclusion chromatography. SDS-PAGE analysis showed a singleband with aproximate molecular mass of 11,4 kDa, suggesting that the inhibitor was successfully purified into a single protein

Diversity of Actinomycetes From Eka Karya Botanical Garden, Bali

A total of 229 strains of actinomycetes were isolated and identified by full sequence of 16S rRNA gene analysis. Samples consisted of 18 soil and 20 leaf-litter were collected from Eka Karya Botanical Garden, Bali Island, Indonesia. Two isolation methods, i.e. SDS-Yeast Extract (SY) and Rehydration-Centrifugation (RC) were used in this study. Based on 16S rRNA gene analysis, isolated actinomycetes may be grouped into 28 genera. Based on molecular analysis of 16S rRNA gene similarities showed that isolated actinomycetes of Eka Karya Botanical Garden origin is diverse. Analysis on 144 isolates from soil samples, resulted in 24 genera and more than 87 species. Streptomyces is the most dominant genus where 65 isolates or 45% from isolated actinomycetes belong to this genus. It was followed by Actinoplanes (25 isolates =17%). From leaf-littersamples, the total number of 85 isolates may be grouped into 9 genera and more than 41 species. The most dominated genus is Actinoplanes (42 isolates =49%) followed by Catenuloplanes (16 isolates=19%)

Screening and activity of yeast-associated with cocoa-bean fermentation against phytopathogenic yeast and fungi

Cocoa-bean fermentation has been associated with the involvement of diverse microbial assemblages which consist of a wide array of bacteria and yeast. We attempted to screen and to identify the potential antifungal yeast from this assemblage against phytopathogenic fungi. We employed in-vitro antagonism assay using agar plug methods to performpreliminary screening from 35 yeast isolates followed by total protein production and measurement with Bradford methods. We found three yeast strains that were effective against Trichoderma sp. T009, and two moulds associated with cocoa (Penicilliumsp. Cocoa2 and Fusariumsp.Cocoa 1). The three bioactive yeast strains were identified as Saccharomyces cerevisiae IDI-002, Hanseniasporauvarum IDE-056 and Hanseniasporauvarum IDE-271 based on molecular identification and phylogenetic analysis. The production of antifungal protein from pure cultures on YEPG media resulted intotal protein concentration between 6.20 - 8.17 mg/L. Cell suspension showed higherinhibitory activity compared to thecell-free supernatant gave indication that antifungal proteins in the bulk fermentation was below the minimal inhibitory concentration to cause the inhibitory effect. Further characterization, purification, and optimization are still needed before the up-scale production of antifungal metabolites and its biological control application

Stability Study of Fermented Milk using Lactiplantibacillus plantarum subsp. plantarum DAD-13 with Alpha Glucosidase Enzyme Inhibitory Activity on Simulated Gastrointestinal Digestion and Storage at Cold Temperature

Fermented milk has bioactive peptides with alpha-glucosidase inhibitor capabilities. To be used widely, it must have stability when it stored and when it enters the human digestive tract. The purpose of this research was to understand the stability of alphaglucosidase inhibitory (AGI) activity of bioactive peptide from fermented milk on simulated gastrointestinal digestion and the stability during storage on cold temperature. Fermented milk was prepared by inoculating L. plantarum subsp. plantarum DAD-13 on sterilized milk for 18 h. The fermented milk was placed in simulated gastrointestinal digestion used consecutive pepsin for 3 h, bile salt and tripsin for 2h and tripsin for 8h. Determination of storage stability was carried out at cold temperature (4oC) for 30 days. Bioactive peptides simulated in the human digestive tract still had AGI abilities even though the values had decreased. The AGI activity of bioactive peptide of fermented milk decreased during digestion. AGI value decreased during storage but still had high inhibitory ability after 30 days (19,0126%). Thus, fermented milk could serve as an antihyperglycemic peptide source and alternative food for maintaining/reducing blood glucose